Doctors implanted tiny battery-powered electrodes deep inside her brain. This revolutionary procedure is Laura’s only hope of reversing the devastating effects of a rare neurological condition.

Laura Herbert: It's so amazing, wow.

Doctor: Yeah, it's cool stuff.

We first met this remarkable 31-year-old six days before her surgery.

Stone Phillips, Dateline corresponde: As we're walking here, the motion in your right leg is just part of the involuntary...

Herbert: Yeah, it's twenty-four, seven, you know? From the moment that I wake up in the morning and I first realize I'm awake, the tremor starts.

Laura suffers from dystonia, a movement disorder that affects a quarter-million Americans. It's caused by abnormal activity in the part of the brain that regulates muscle control. Dystonia forces parts of Laura’s body into involuntary and sometimes agonizing twists, spasms, and contractions.

Herbert: The body just wants to do what it wants to do, when it wants to do it. This can be very, inconvenient.

On a typical morning, she and her fiancé, Luke, head out of their Manhattan apartment for breakfast.Since a casual stroll to the coffee shop, or anywhere else, is out of the question, Laura relies on a tricycle to get around the neighborhood.

Unfazed by New York City’s traffic, she pedals to her job at a cable television network. She enters work by the back door. It's closer to the elevator, and allows her to hide from the unwanted stares she often gets as she heads to her office, in reverse. Laura's dystonia makes walking a painful task; she actually finds it easier going backwards.

Herbert: On top of being uncomfortable physically you sort of learn to keep your head down, because I'll get really red-faced.

Phillips: You feel the stares.

Herbert: Absolutely.

Medication and other therapies failed to halt the disorder, which began out of the blue when Laura was just 12 years old. Starting in her feet, the spasms eventually progressed to a leg, her torso, shoulders, and her right hand, so she's taught herself to make do with her left.

For all its striking symptoms, many doctors remain unfamiliar with dystonia. In fact, Laura was misdiagnosed for ten years. Doctors and even her parents believed her physical symptoms were all in her head.

Phillips: And so instead of prescribing treatment for you they prescribed psychotherapy.

Herbert: Miraculously, none of them had cured me of my dystonia. And, in fact, I just got worse.

By the time she was correctly diagnosed in her early 20s, her body had slipped further from her control, to the point where now her daily life has to be choreographed well in advance.

Herbert: I have to maximize all of my trips around the office because I don't get up more than twice or three times a day from my desk.

But what Laura really wants is to take back control of her body. And finally, there may be a way to do it; with a pacemaker, like the kind used for heart patients, but surgically implanted, inside the brain.

Set to operate at Beth Israel Medical Center in New York, neurosurgeon Ron Alterman thinks these "brain pacemakers" can help Laura.

Dr. Ron Alterman: I think she'll be able to walk much better and have better use of her hands.

The day before surgery, with her mother looking on, Laura parts with the long hair she'd had for 15 years. Finally, on the morning of the surgery, there is nothing to do but wait, and hope.

Doctors will place two electrodes in that target area, one on each side of her brain. They will be connected to battery-powered controls in Laura’s chest. The idea is, the electrical stimulation they send into the brain will block the signals that cause Dystonia's symptoms. One slip and her vision could be harmed, or her tremors made worse. Laura feels no pain, but needs to be awake and responsive enough to help doctors map her brain and find their target. With so little margin for error, doctors push the electrodes in. The doctors are navigating the electrodes’ placement, by sound. This static hiss is actually the electrical activity of individual cells in Laura’s brain, translated into audio. When doctors hear the unique sound of the cells that control muscle movement, they know they're in the right place.

The 5-hour operation went flawlessly. For Laura the only question that matters now is, will it work?

Two weeks later, in a wig as vibrant as her personality, Laura heads to Beth Israel hospital. Her pacemakers are about to be turned on.

Laura's Neurologist, Dr. Michele Tagliati, gives the green light. And moments later his team uses this hand-held remote control to power up Laura’s hardware, right through her skin.

Herbert: I'm starting to get a weird feeling on the back of my throat...

Therapist: Tell me if it goes away.

Herbert: Weird. My lips and tongue just went numb.

By her next appointment, two weeks later, there's already a striking development. Laura is walking forwards with greater ease. And these boots have heels.

Even as her pacemaker settings are fine-tuned, it’s clear to see the brain stimulation is having an effect on her hands. Laura stretches her arms out in front, they're steady.

Herbert: Insane! I mean, that's crazy! Nice job.

But there's an even greater surprise in store, when Laura is encouraged to try something she hasn't done in years.

Dateline wires the home of a volunteer, Jenny, from top to bottom with hidden cameras. Then she called repairmen to her house for a simple problem we created as a test with Jenny's pool. NBC's Chris Hansen reports.